the gunman has been identified as paul anthony ciancia. >> he's 23 years old. he's a u.s. citizen. he's formerly a resident of new jersey. we are currently investigating his background and more about him. >> reporter: the incident raised some questions about security inside the nation's airports, especially a sprawling complex like l.a.x. >> a lot of airports you have one main entranceway like atlanta that gets you into all the areas of the airport, but it's much easier to secure it. airports like l.a.x., dallas/fort worth, kansas city, there are so many portals into the airports and so many areas to secure that they're tough and l.a.x. is one of those tough airports with so many different portals in. they have additional issues that maybe some other airports like hartsfield don't have. >> reporter: hundreds of flights to and from l.a.x. were affected throughout friday. hours after the incident many passengers remain frustrated. >> we were on the tarmac five hours. first they moved us to international. then they said we'd have buses take us off. >> reporter: and there are passeng